<?php

if (!defined('BASEPATH'))
  exit('No direct script access allowed');
/**
 * CodeIgniter
 *
 * An open source application development framework for PHP 5.1.6 or newer
 *
 * @package		CodeIgniter
 * @author		ExpressionEngine Dev Team
 * @copyright	Copyright (c) 2008 - 2011, EllisLab, Inc.
 * @license		http://codeigniter.com/user_guide/license.html
 * @link		http://codeigniter.com
 * @since		Version 1.0
 * @filesource
 */
// ------------------------------------------------------------------------

/**
 * Trackback Class
 *
 * Trackback Sending/Receiving Class
 *
 * @package		CodeIgniter
 * @subpackage	Libraries
 * @category	Trackbacks
 * @author		ExpressionEngine Dev Team
 * @link		http://codeigniter.com/user_guide/libraries/trackback.html
 */
class CI_Trackback {

  var $time_format = 'local';
  var $charset = 'UTF-8';
  var $data = array('url' => '', 'title' => '', 'excerpt' => '', 'blog_name' => '', 'charset' => '');
  var $convert_ascii = TRUE;
  var $response = '';
  var $error_msg = array();

  /**
   * Constructor
   *
   * @access	public
   */
  public function __construct() {
    log_message('debug', "Trackback Class Initialized");
  }

  // --------------------------------------------------------------------

  /**
   * Send Trackback
   *
   * @access	public
   * @param	array
   * @return	bool
   */
  function send($tb_data) {
    if (!is_array($tb_data)) {
      $this->set_error('The send() method must be passed an array');
      return FALSE;
    }

    // Pre-process the Trackback Data
    foreach (array('url', 'title', 'excerpt', 'blog_name', 'ping_url') as $item) {
      if (!isset($tb_data[$item])) {
        $this->set_error('Required item missing: ' . $item);
        return FALSE;
      }

      switch ($item) {
        case 'ping_url' : $$item = $this->extract_urls($tb_data[$item]);
          break;
        case 'excerpt' : $$item = $this->limit_characters($this->convert_xml(strip_tags(stripslashes($tb_data[$item]))));
          break;
        case 'url' : $$item = str_replace('&#45;', '-', $this->convert_xml(strip_tags(stripslashes($tb_data[$item]))));
          break;
        default : $$item = $this->convert_xml(strip_tags(stripslashes($tb_data[$item])));
          break;
      }

      // Convert High ASCII Characters
      if ($this->convert_ascii == TRUE) {
        if ($item == 'excerpt') {
          $$item = $this->convert_ascii($$item);
        } elseif ($item == 'title') {
          $$item = $this->convert_ascii($$item);
        } elseif ($item == 'blog_name') {
          $$item = $this->convert_ascii($$item);
        }
      }
    }

    // Build the Trackback data string
    $charset = (!isset($tb_data['charset'])) ? $this->charset : $tb_data['charset'];

    $data = "url=" . rawurlencode($url) . "&title=" . rawurlencode($title) . "&blog_name=" . rawurlencode($blog_name) . "&excerpt=" . rawurlencode($excerpt) . "&charset=" . rawurlencode($charset);

    // Send Trackback(s)
    $return = TRUE;
    if (count($ping_url) > 0) {
      foreach ($ping_url as $url) {
        if ($this->process($url, $data) == FALSE) {
          $return = FALSE;
        }
      }
    }

    return $return;
  }

  // --------------------------------------------------------------------

  /**
   * Receive Trackback  Data
   *
   * This function simply validates the incoming TB data.
   * It returns FALSE on failure and TRUE on success.
   * If the data is valid it is set to the $this->data array
   * so that it can be inserted into a database.
   *
   * @access	public
   * @return	bool
   */
  function receive() {
    foreach (array('url', 'title', 'blog_name', 'excerpt') as $val) {
      if (!isset($_POST[$val]) OR $_POST[$val] == '') {
        $this->set_error('The following required POST variable is missing: ' . $val);
        return FALSE;
      }

      $this->data['charset'] = (!isset($_POST['charset'])) ? 'auto' : strtoupper(trim($_POST['charset']));

      if ($val != 'url' && function_exists('mb_convert_encoding')) {
        $_POST[$val] = mb_convert_encoding($_POST[$val], $this->charset, $this->data['charset']);
      }

      $_POST[$val] = ($val != 'url') ? $this->convert_xml(strip_tags($_POST[$val])) : strip_tags($_POST[$val]);

      if ($val == 'excerpt') {
        $_POST['excerpt'] = $this->limit_characters($_POST['excerpt']);
      }

      $this->data[$val] = $_POST[$val];
    }

    return TRUE;
  }

  // --------------------------------------------------------------------

  /**
   * Send Trackback Error Message
   *
   * Allows custom errors to be set.  By default it
   * sends the "incomplete information" error, as that's
   * the most common one.
   *
   * @access	public
   * @param	string
   * @return	void
   */
  function send_error($message = 'Incomplete Information') {
    echo "<?xml version=\"1.0\" encoding=\"utf-8\"?" . ">\n<response>\n<error>1</error>\n<message>" . $message . "</message>\n</response>";
    exit;
  }

  // --------------------------------------------------------------------

  /**
   * Send Trackback Success Message
   *
   * This should be called when a trackback has been
   * successfully received and inserted.
   *
   * @access	public
   * @return	void
   */
  function send_success() {
    echo "<?xml version=\"1.0\" encoding=\"utf-8\"?" . ">\n<response>\n<error>0</error>\n</response>";
    exit;
  }

  // --------------------------------------------------------------------

  /**
   * Fetch a particular item
   *
   * @access	public
   * @param	string
   * @return	string
   */
  function data($item) {
    return (!isset($this->data[$item])) ? '' : $this->data[$item];
  }

  // --------------------------------------------------------------------

  /**
   * Process Trackback
   *
   * Opens a socket connection and passes the data to
   * the server.  Returns TRUE on success, FALSE on failure
   *
   * @access	public
   * @param	string
   * @param	string
   * @return	bool
   */
  function process($url, $data) {
    $target = parse_url($url);

    // Open the socket
    if (!$fp = @fsockopen($target['host'], 80)) {
      $this->set_error('Invalid Connection: ' . $url);
      return FALSE;
    }

    // Build the path
    $ppath = (!isset($target['path'])) ? $url : $target['path'];

    $path = (isset($target['query']) && $target['query'] != "") ? $ppath . '?' . $target['query'] : $ppath;

    // Add the Trackback ID to the data string
    if ($id = $this->get_id($url)) {
      $data = "tb_id=" . $id . "&" . $data;
    }

    // Transfer the data
    fputs($fp, "POST " . $path . " HTTP/1.0\r\n");
    fputs($fp, "Host: " . $target['host'] . "\r\n");
    fputs($fp, "Content-type: application/x-www-form-urlencoded\r\n");
    fputs($fp, "Content-length: " . strlen($data) . "\r\n");
    fputs($fp, "Connection: close\r\n\r\n");
    fputs($fp, $data);

    // Was it successful?
    $this->response = "";

    while (!feof($fp)) {
      $this->response .= fgets($fp, 128);
    }
    @fclose($fp);


    if (stristr($this->response, '<error>0</error>') === FALSE) {
      $message = 'An unknown error was encountered';

      if (preg_match("/<message>(.*?)<\/message>/is", $this->response, $match)) {
        $message = trim($match['1']);
      }

      $this->set_error($message);
      return FALSE;
    }

    return TRUE;
  }

  // --------------------------------------------------------------------

  /**
   * Extract Trackback URLs
   *
   * This function lets multiple trackbacks be sent.
   * It takes a string of URLs (separated by comma or
   * space) and puts each URL into an array
   *
   * @access	public
   * @param	string
   * @return	string
   */
  function extract_urls($urls) {
    // Remove the pesky white space and replace with a comma.
    $urls = preg_replace("/\s*(\S+)\s*/", "\\1,", $urls);

    // If they use commas get rid of the doubles.
    $urls = str_replace(",,", ",", $urls);

    // Remove any comma that might be at the end
    if (substr($urls, -1) == ",") {
      $urls = substr($urls, 0, -1);
    }

    // Break into an array via commas
    $urls = preg_split('/[,]/', $urls);

    // Removes duplicates
    $urls = array_unique($urls);

    array_walk($urls, array($this, 'validate_url'));

    return $urls;
  }

  // --------------------------------------------------------------------

  /**
   * Validate URL
   *
   * Simply adds "http://" if missing
   *
   * @access	public
   * @param	string
   * @return	string
   */
  function validate_url($url) {
    $url = trim($url);

    if (substr($url, 0, 4) != "http") {
      $url = "http://" . $url;
    }
  }

  // --------------------------------------------------------------------

  /**
   * Find the Trackback URL's ID
   *
   * @access	public
   * @param	string
   * @return	string
   */
  function get_id($url) {
    $tb_id = "";

    if (strpos($url, '?') !== FALSE) {
      $tb_array = explode('/', $url);
      $tb_end = $tb_array[count($tb_array) - 1];

      if (!is_numeric($tb_end)) {
        $tb_end = $tb_array[count($tb_array) - 2];
      }

      $tb_array = explode('=', $tb_end);
      $tb_id = $tb_array[count($tb_array) - 1];
    } else {
      $url = rtrim($url, '/');

      $tb_array = explode('/', $url);
      $tb_id = $tb_array[count($tb_array) - 1];

      if (!is_numeric($tb_id)) {
        $tb_id = $tb_array[count($tb_array) - 2];
      }
    }

    if (!preg_match("/^([0-9]+)$/", $tb_id)) {
      return FALSE;
    } else {
      return $tb_id;
    }
  }

  // --------------------------------------------------------------------

  /**
   * Convert Reserved XML characters to Entities
   *
   * @access	public
   * @param	string
   * @return	string
   */
  function convert_xml($str) {
    $temp = '__TEMP_AMPERSANDS__';

    $str = preg_replace("/&#(\d+);/", "$temp\\1;", $str);
    $str = preg_replace("/&(\w+);/", "$temp\\1;", $str);

    $str = str_replace(array("&", "<", ">", "\"", "'", "-"), array("&amp;", "&lt;", "&gt;", "&quot;", "&#39;", "&#45;"), $str);

    $str = preg_replace("/$temp(\d+);/", "&#\\1;", $str);
    $str = preg_replace("/$temp(\w+);/", "&\\1;", $str);

    return $str;
  }

  // --------------------------------------------------------------------

  /**
   * Character limiter
   *
   * Limits the string based on the character count. Will preserve complete words.
   *
   * @access	public
   * @param	string
   * @param	integer
   * @param	string
   * @return	string
   */
  function limit_characters($str, $n = 500, $end_char = '&#8230;') {
    if (strlen($str) < $n) {
      return $str;
    }

    $str = preg_replace("/\s+/", ' ', str_replace(array("\r\n", "\r", "\n"), ' ', $str));

    if (strlen($str) <= $n) {
      return $str;
    }

    $out = "";
    foreach (explode(' ', trim($str)) as $val) {
      $out .= $val . ' ';
      if (strlen($out) >= $n) {
        return trim($out) . $end_char;
      }
    }
  }

  // --------------------------------------------------------------------

  /**
   * High ASCII to Entities
   *
   * Converts Hight ascii text and MS Word special chars
   * to character entities
   *
   * @access	public
   * @param	string
   * @return	string
   */
  function convert_ascii($str) {
    $count = 1;
    $out = '';
    $temp = array();

    for ($i = 0, $s = strlen($str); $i < $s; $i++) {
      $ordinal = ord($str[$i]);

      if ($ordinal < 128) {
        $out .= $str[$i];
      } else {
        if (count($temp) == 0) {
          $count = ($ordinal < 224) ? 2 : 3;
        }

        $temp[] = $ordinal;

        if (count($temp) == $count) {
          $number = ($count == 3) ? (($temp['0'] % 16) * 4096) + (($temp['1'] % 64) * 64) + ($temp['2'] % 64) : (($temp['0'] % 32) * 64) + ($temp['1'] % 64);

          $out .= '&#' . $number . ';';
          $count = 1;
          $temp = array();
        }
      }
    }

    return $out;
  }

  // --------------------------------------------------------------------

  /**
   * Set error message
   *
   * @access	public
   * @param	string
   * @return	void
   */
  function set_error($msg) {
    log_message('error', $msg);
    $this->error_msg[] = $msg;
  }

  // --------------------------------------------------------------------

  /**
   * Show error messages
   *
   * @access	public
   * @param	string
   * @param	string
   * @return	string
   */
  function display_errors($open = '<p>', $close = '</p>') {
    $str = '';
    foreach ($this->error_msg as $val) {
      $str .= $open . $val . $close;
    }

    return $str;
  }

}

// END Trackback Class

/* End of file Trackback.php */
/* Location: ./system/libraries/Trackback.php */